Rather than the mechanical red/yellow/green caps that you can get but you have to buy them pre-set for the pressure you want your tires set to these caps have an LED and automatically set to whatever pressure you have in the tire when you put it on. IOW, you like to run your front at 44psi and your back at 42psi. So you air up the tires to the exact pressure, screw on the new caps and they self-program. You can also set them for when they alert you...as little as 4psi drop is possible (I wish it was a 2 psi drop, but 4's not terrible). LED Tire Alert Pressure Indicator (four per pack): TerraPass
The same or similar for only $24 for a set of 4 at http://www.amazon.com/Tire-Alert-Self-Calibrating-Pressure-Valve/dp/B0009RSR36. Product Description The LED Tire Alert Valve Cap is a small device that will start blinking if the tire pressure falls 4 psi below the correct pressure. It is an active warning, which will be seen by the driver as she/he approaches the vehicle. The Valve Cap is designed to replace the regular dust cap on a tire. Therefore it will fit most passenger cars, pick up trucks, large trucks, tractor trailers, fork lifts, motorcycles, bicycles, lawn mowers or wheel barrels. The Valve Cap is so small (approx. 1" x ½ ) and light (only 0.3 oz) that it will have no impact on the wheel balancing or the appearance of the vehicle. Features of the LED Tire Alert Valve Cap: Durable design The Cap is designed to withstand even the toughest conditions. The body is made of nickel-plated aluminum and the clear cap is made of clear Polycarbonate. It has no moving parts except a membrane, which will flex slightly if the tire pressure drops. The Valve Cap is entirely sealed and therefore no moisture, dust or dirt can enter into it. Self-Calibrating The Valve Cap is self-calibrating. When the cap is mounted on the valve stem the first time, it will memorize that tire pressure. The cap is calibrated for life and does not need to, and cannot be, updated later. The Cap can be calibrated to any tire pressure between 20 and 110 psi. Since most car manufacturers recommend having different tire pressures for your front tires vs. your rear tires, the ability to self-calibrate gives you the flexibility to calibrate each valve cap to the appropriate pressure Easy to install Since the Valve Cap is self-calibrating no further calibration needs to be done by the installer. The Valve Cap is also 100% self-contained with onboard batteries. All four LED Tire Alert Valve Caps can be installed in just a few seconds more than it takes to check the tire pressure and it does not need to be done by a trained technician.
like most of the tchotkes in the world, I will be interested to know if it lasts for more than a month. Please keep a record so we can gues the MTBF.
doc, on that second monitor...do i understand that it has to be set one time and that it is to be set at "the most common pressures".if so does that mean that you my not be able to set it a 42lbs or 40 lbs rerspectively??
I think they're both basically the same. AFAIK it calibrates to whatever pressure you have in the tire when you put the cap on. Doc, I don't have either of these. Just posted for interest. The reviews suggest a fairly high 'leak' rate and the batteries only last about 2 years (and I don't know if they're replaceable).
doc and gang i think ill give that 2nd one a shot and order it now from amazon. ill let everyone know how i like(hate) them.
Interesting.. it can only be set once... so if I swapped tyres (e.g. Integrity to WR), you'll need another set unless you wanna keep the same PSI as your previous tyres. However, at $24, shouldn't be that bad to get another set. Just pass on the ones you have I suppose.
So is there a better tire pressure for Nokian WR than 42/40 PSI, or are you just referring to lower pressure for winter driving?
No I was just referring to a situation where if you had to switch tyre brands or even just tyre models and you want to transfer that set of LED caps, you won't be able to change pressure. Off topic a bit, how's 42/40? I'm running 40/38.
just in passing, doc and the gang: i did order those and when they come in i will give a report to my prii peops.
I had the tire pressure valve stem covers that changed from red to green in my other car. They worked okay but be careful of the material they are made of. The ones I had fused onto the valve stems due to corrosion (cathodic reaction?) and it took vise grips to get them off. Came real close to damaging my valve stems. Also, they can be another potential source of a slow leak themselves.
Also when tires are rotated you need to rotate the monitors (since the front tires should be at +2 psi of the rear). Gabe
all righty!!! a guinea pig.... ty fred, let us know how it goes... for $24...seems a small price to pay
I worry that these things would leak. To sense the pressure, they need to depress the needle in the valve stem to allow the airspace under the cap to be pressurized. The pressure is now being held in by the cap rather than the valve, and the area for leaking is bigger. Not obvious whether this would be a real problem or not. One presumes it isn't or word would get out, but...interested to hear how well they work. The idea is certainly intriguing.
im thinking about selling my results when my stems arrive. say like....ummmmm$24 . yeah thats the ticket.
well at least at 36-38 psi, you would be alerted to the problem. having had two times when the TPMS alerted me to low pressure, once at 28 psi, the other at 26 psi both from 40 psi rear tires, i'd be willing to take the risk. if the cap is broken, the valve stem will then be re-seated... so why not? waaaay better than what we have now
Wow! Awesome find! I had looked at these too: ONE TOUCH ELECTRONIC TIRE PRESSURE MONITORING SYSTEM - JCWhitney Truck Parts I like the ones you found because there is no dumb magic wand to have to carry around (or lose). Cheers!
